Single blade electric shutter

ABSTRACT

A single blade electric shutter for opening and closing a camera aperture, comprising a first movable release lever, a second movable release lever in parallel relation to the first lever, and springs for urging the release levers in a first direction. A shutter blade is pivotally connected to the first and second levers and is movable to an open position when the first lever is moved in the first direction relative to the second lever. A locking member is mounted on a movable release rod and is adapted to engage the first lever to maintain it in a first position against the urging force of the spring. When the release rod is moved in a predetermined direction, the locking member is released from the first lever. A locking assembly is adapted to engage and disengage the second lever to control the shutter speed, and a time constant electric circuit is connected to the locking assembly to control its actuation.

Ohmura [5 1 SINGLE BLADE ELECTRIC SHUTTER [75] Inventor: lliroshiOhmura, Minato-ku, Tokyo,

Japan 73 Assignee: Fuji Photo Film Co., 1.16.,

Kanagawa, Japan [22] Filed: Dec. 17, 1971 [21] Appl. No.: 209,045

[30] Foreign Application Priority Data Dec. 17, 1970 Japan 45/126324[52] US. Cl. 95/59 [51] Int. Cl. G03b 9/10 [58] Field of Search. 95/53E, 55, 59

[56] References Cited I UNITED STATES PATENTS 2,978,970 4/1961Fahlenberg 95/63 X 3,241,471 3/1966 Burgarella, 95/55 FOREIGN PATENTSORAPPLICATIONS 78,318

11/1894 Germany 95/59 Primary Examiner-John M. Horan Attorney-Richard C,Sughrue, Donald E. Zinn et al.

57 ABSTRACT A single blade electric shutter for opening and closing acamera aperture, comprising a first movable release lever, a secondmovable release lever in parallel relation to the first lever, andsprings for urging the release levers in a first direction. A shutterblade is pivotally connected to the first and second levers and ismovable to an open position when the first lever is moved in the firstdirection relative to the second lever. A locking member is mounted on amovable release rod and is adapted to engage the first lever to maintainit in a first position against the urging force of the spring. When therelease rod is moved in a predetermined direction, the locking member isreleased from the first lever. A locking assembly is adapted to engageand disengage the second lever to control the shutter speed, and a timeconstant electric circuit is connected to the locking assembly tocontrol its actuation.

6 Claims, 3 Drawing Figures SINGLE BLADE ELECTRIC SHUTTER BACKGROUND OFTHE INVENTION The present invention relates to a single blade typeelectric shutter for cameras.

A single blade type shutter has been known in the art to make theconstruction of the photographic camera simple. Most of the single bladetype photographic shutters have been of the mechanical type. Since thesingle blade type shutters are to be used in a simple 'camera in mostcases, the construction thereof is preferred to be as simple aspossible.

SUMMARY OF THE INVENTION The primary object of the present invention isto pro vide a single blade type shutter which is of extremely simpleconstruction.

Another object of the present invention is to provide a single bladetype shutter utilizing an electromagnet to further simplify theconstruction thereof.

A further object of the present invention is to provide a single bladeelectric shutter which can be manufactured at very low cost.

In order to accomplish the above objects of the invention, two releaselevers are provided in parallel with each other to which a singleshutter blade is pivotally mounted. One of the levers is released bypressing a release rod down, and the other of the levers is released byenergizing an electromagnet which is connected in a time constantcircuit acting in response to exposure value.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 3 is a view similar to FIGS. 1and 2, showing the state in which the shutterblade is closed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Now referring to the drawing,the reference numeral 1 indicates a shutter blade which is mounted to afirst release lever 2 and a second release lever 3 at pivots 4 and 5,respectively.

The levers 2, 3 are each provided with a hook 6, 7

and connected with a tension spring 8, 9, respectively, so as to beurged to the left as seen in the drawings. The reference numeral 10indicates a bent portion provided at the left end of the lever 2which'serves to align both of the levers 2, 3.

a shutter release rod 12 is provided with a hook lever 11 which ispivotally mounted thereto and engaged with the hook 6. The hook lever 11is biased in the clockwise direction by a spring 11a. The referencenumeral 12 indicates a tension spring urging the shutter release rod 12upwardly. A hook lever or latching means 13 is pivotally disposed in aposition to be engaged with the hook 7 of the second lever 3. The hooklever 13 is urged in the counterclockwise direction by a tension spring16 and is adapted to be rotated in a clockwise directionby anelectromagnet 14. When the hook lever 13 is in its extreme rightposition, it is in engagement with the hook 7 of the second lever 3.

In FIG. 1, the shutter blade 1 closes the aperture 15 with the first andsecond levers 2 and 3 located in the right extremity engaged'with'thehook levers l1 and 13 at the hooks 6 and 7, respectively. When theshutter rod 12 is pressed downwardly from the state of FIG. 1, the hook11 is also moved downwardly and released from the hook 6 of the firstlever 2. Accordingly, the first lever 2 is moved leftward by the tensionof the spring 8 to move the pivot 4 leftward. Thus, the shutter blade 1isopened as shown in FIG. 2. The direction of movement of the lever 2and the blade 1 is indicated by arrows.

At the time when the shutter release rod 12 is pressed downwardly, themagnet 14 is madeconductive and attracts the hook lever 13 to keep thehook lever 13 in its engaging position as shown in FIG. 2. When thefirst lever 2 is moved to its right extremity, the time constant circuit(not shown) is closed. The time constant circuit is well known in thephotography field in which the exposure is made automatically inresponse to the illumination condition and other factors to determinethe exposure value. Such time constant circuits are disclosed in UnitedStates Pat. Nos. 3,326,103 and 3,205,795. I

When the time constant circuit is closed, charging of a capacitor in thecircuit is started. The period for which the capacitor is charged isdetermined by the sensitivity of the film and brightness of illuminationand other factors affecting the right shutter speed. When the chargingof the capacitor is finished, the magnet 14 is deenergized and the hooklever 13 is rotated counterclockwise by the force of the spring 16.Thus, the hook lever 13 is disengaged from the second lever 3. Then, thesecond lever 3 is moved leftward by the tension of the spring 9.Accordingly, the shutter blade 1 is rotated clockwise to close theaperture 15 as shown in FIG. 3. Since the shutter blade 1 is displacedfrom the initial position as shown in FIG. 1 when it is in its finalposition as shown in FIG. 3, the shape of the shutter blade I isrequired to have a laterally extending large portion la to close theaperture 15. i

In order to charge the shutter mechanis mafter it is released, a shuttercharging lever 17 is moved rightward to move the. first shutter releaselever 2 rightward. An erected edge portion 2a of the first release lever2 is pushed by the shutter charging lever 17.

What is claimed is:

1. A single blade electric shutter comprising a first release lever, asecond release lever slidably supported in parallel relation with saidfirst release lever, mechanical biasing means for solely urging saidrelease levers in a first direction, a shutter blade pivotally connectedgaging and disengaging said second release lever for determining theshutter speed, and an electric time constant circuit controlling theperiod for actuating said engaging and disengaging means, whereby saidshutter blade is mechanically movedsolely by said mechanical bearingmeans to open and close the aperture of the 3 wherein said secondrelease lever has a hook portion for engagement with said hook lever.

5. A single blade electric shutter as defined in claim 1 wherein meansis provided to align said first and second release levers when saidshutter blade is in a shutsaid second lever for controlling the timeperiod said shutter blade is in the open position, and electric timeconstant circuit means for controlling the actuation of said engagingand disengaging means.

1. A single blade electric shutter comprising a first release lever, asecond release lever slidably supported in parallel relation with saidfirst release lever, mechanical biasing means for solely urging saidrelease levers in a first direction, a shutter blade pivotally connectedto said release levers, means for maintaining said first release leverin a first position against the force of said urging means, a shutterrelease rod for releasing said first release lever from said maintainingmeans when said rod is moved in a predetermined direction,electromagnetic controlled mechanical latching means for engaging anddisengaging said second release lever for determining the shutter speed,and an electric time constant circuit controlling the period foractuating said engaging and disengaging means, whereby said shutterblade is mechanically moved solely by said mechanical bearing means toopen and close the aperture of the camera in respoNse to the actuatingof said shutter release rod and the time constant.
 2. A single bladeelectric shutter as defined in claim 1 wherein said first release leveris provided with a hook portion, and said maintaining means comprises ahook lever mounted on said shutter release rod for engagement with saidhook portion of said first release lever.
 3. A single blade electricshutter as defined in claim 1 wherein said electromagnetic controlledmechanical latching means for engaging and disengaging said secondrelease lever comprises a hook lever urged in the releasing direction,and an electromagnet for effecting engagement of said hook lever withsaid second lever.
 4. A single blade electric shutter as defined inclaim 3 wherein said second release lever has a hook portion forengagement with said hook lever.
 6. A single blade electric shuttercomprising a first movable release lever, a second movable release leverdisposed in parallel relation to said first lever, mechanical biasingmeans for solely urging said release levers in a first direction, ashutter blade pivotally connected to both said first and second leversand movable to an open position when said first lever is moved in thefirst direction relative to said second lever, a movable shutter releaserod, means for engaging said first lever to maintain it in a firstposition against the force of said urging means, said engaging meansbeing released from said first lever when said release rod is moved in apredetermined direction, electromagnetic controlled mechanical latchingmeans for engaging and disengaging said second lever for controlling thetime period said shutter blade is in the open position, and electrictime constant circuit means for controlling the actuation of saidengaging and disengaging means.
 6. A single blade electric shutter asdefined in claim 1 wherein means is provided to align said first andsecond release levers when said shutter blade is in a shutter-closedposition.